The purpose of this contract is to test the validity of two alternative representations of the motion of the cricoarytenoid joint. The Contractor will accomplish the following objectives: A. To include a high resolution mathematical representation of the joint surfaces and the muscle actions in the model. B. To evaluate the motion produced at the joint in each of three directions (rocking, sliding, and rotation). C. To compare the accuracy of two different descriptions of cricoarytenoid joint action. D. To determine the correspondence between actual movement data and simulated movement during joint motion in each direction and combinations of directions. The outcome of this contract will be evidence on the most accurate representation of cricoarytenoid joint motion in the human larynx.